Tracheoesophageal Fistula (TEF) - 10 Mark Answer (MS ENT)

Definition

Embryology

• Incidence: 1 in 3000-4500 live births; slight male predominance
• TEF is the most common birth defect of the lower respiratory tract

Classification (Gross-Vogt / Five Types)

The H-type fistula is particularly important as it has no esophageal atresia and may present late with recurrent chest infections.

Associated Anomalies

• V - Vertebral anomalies
• A - Anorectal defects (imperforate anus)
• C - Cardiac defects (~38% - most common associated anomaly)
• TE - Tracheoesophageal fistula
• R - Renal anomalies (~15%)
• L - Limb defects (radial limb hypoplasia)

Clinical Features

Congenital TEF with EA (Types A-D)

• Polyhydramnios (fetus cannot swallow amniotic fluid; no gastric filling)
• Failure to visualize the fetal stomach on ultrasound

1. Excessive drooling/frothing from birth (accumulation of saliva in blind esophageal pouch)
2. Choking and cyanosis with first feed - aspiration of milk
3. Abdominal distension - air enters stomach via fistula during crying

• Repeated regurgitation and respiratory distress
• Chemical pneumonitis from reflux of gastric acid through distal TEF into lungs
• Inability to pass a nasogastric tube (coils in the upper pouch at ~10 cm from gum margin)

H-type TEF (Type E) - presents later

• Recurrent chest infections (aspiration pneumonia)
• Coughing/choking during feeds ("Oehlecker test" - positive coughing when methylene blue dye is injected into esophagus)
• Abdominal distension (borborygmi/gas)
• Subtle symptoms - may be diagnosed in later infancy or childhood

Acquired TEF

• Prolonged cuffed endotracheal/tracheostomy tube (pressure necrosis of the posterior "party wall" between trachea and esophagus, especially with concurrent large-bore NG tube)
• Esophageal or tracheal malignancy
• Trauma, foreign body, radiation necrosis
• Occurs in <1% of tracheostomies

Diagnosis

Neonatal (Types A-D)

1. Inability to pass orogastric/nasogastric tube - tube coils at 10 cm; confirmed on chest X-ray (coiled tube in upper pouch)
2. Plain chest X-ray:
   • Coiled catheter in upper pouch
   • Air in the stomach/GI tract = confirms distal fistula (Type C)
   • Absent gastric air = isolated EA (Type A)
   • Lung consolidation/collapse from aspiration
3. Contrast esophagram (used cautiously) - documents the anatomy; risk of aspiration
4. Echocardiography - to exclude cardiac anomalies (mandatory pre-operatively)
5. Renal ultrasound, skeletal X-rays - screen for VACTERL anomalies

H-type TEF

1. Barium esophagram (videofluoroscopy) - may miss small fistulas; H-type fistula typically runs obliquely (tracheal opening is superior to esophageal opening)
2. Bronchoscopy + esophagoscopy - gold standard; methylene blue or Lipiodol injection into esophagus identifies the fistula opening in the trachea

Pre-operative Management

1. Nurse in 30-45° head-up position to minimize aspiration
2. Sump catheter (Replogle tube) on continuous suction in the upper pouch
3. IV antibiotics - for aspiration pneumonia
4. IV fluids / total parenteral nutrition
5. Avoid positive pressure ventilation if possible (worsens gastric distension via fistula)
6. If ventilation is essential - place ETT tip distal to fistula; use low-pressure ventilation
7. Echocardiography - identify cardiac anomalies; determines operative approach (left-sided arch = right thoracotomy)
8. Surgery is not a true emergency unless ventilation is impossible; aim for repair within 24-48 hrs of stabilization

• Group A: >2.5 kg, healthy - low risk
• Group B: 1.8-2.5 kg, or mild pneumonia or moderate anomaly
• Group C: <1.8 kg, or severe pneumonia or severe cardiac anomaly - high risk

Surgical Treatment

Standard Repair (Type C - most common)

1. Identify and divide the azygos vein
2. Identify and ligate/divide the fistula at its tracheal end (tracheal side closed with absorbable sutures)
3. Mobilise proximal and distal esophageal pouches
4. Primary end-to-end esophageal anastomosis

Long-gap EA (gap >3 cm or 2 vertebral bodies)

• Foker technique - external traction sutures to gradually elongate the esophageal stumps prior to anastomosis
• Gastric transposition or colonic/jejunal interposition - if primary anastomosis not possible

H-type TEF (Type E)

• Right cervical approach (fistula usually lies at C5-C7 level)
• Fistula is divided and both ends closed
• Alternatively, endoscopic obliteration with cauterization or trichloroacetic acid (especially for recurrent fistulas)

Acquired TEF (Post-tracheostomy)

• Interposition of viable muscle flap (sternohyoid, sternocleidomastoid, or strap muscles) between the repaired tracheal and esophageal defects
• Esophageal stenting as a temporizing measure in malignant TEF

Complications

Post-operative Complications

Prognosis

• With modern neonatal surgical care, survival exceeds 90% in uncomplicated cases
• Mortality is determined mainly by severity of associated cardiac anomalies and degree of prematurity
• Long-term quality of life is good in most survivors, though GERD and dysmotility require ongoing management

Summary Points for MS ENT Exam

• Most common type = Type C (EA + distal TEF) - 85%
• Commonest presentation = excessive drooling, cyanosis with feeds, abdominal distension
• Key investigation = inability to pass NG tube + chest X-ray
• Approach = right extrapleural thoracotomy
• Operation = fistula ligation + primary esophageal anastomosis
• Most common long-term complication = anastomotic stricture + GERD
• H-type TEF = no EA, presents late, diagnosed by esophagoscopy/bronchoscopy, repaired via cervical approach
• Acquired TEF = most commonly from prolonged tracheostomy + NG tube (pressure necrosis of party wall)